In resource-constrained Internet-of-Things networks, the use of conventional message authentication codes (MACs) to provide message authentication and integrity is not possible due to the large size of the MAC output. A straightforward yet naive solution to this problem is to employ a truncated MAC which undesirably sacrifices cryptographic strength in exchange for reduced communication overhead. In this article, we address this problem by proposing a novel approach for message authentication called cumulative MAC (CuMAC), which consists of two distinctive procedures: 1) aggregation and 2) accumulation. In aggregation, a sender generates compact authentication tags from segments of multiple MACs by using a systematic encoding procedure. In accumulation, a receiver accumulates the cryptographic strength of the underlying MAC by collecting and verifying the authentication tags. Embodied with these two procedures, CuMAC enables the receiver to achieve an advantageous tradeoff between the cryptographic strength and the latency in the processing of the authentication tags. Furthermore, for some latency-sensitive messages where this tradeoff may be unacceptable, we propose a variant of CuMAC that we refer to as CuMAC with speculation (CuMAC/S). In addition to the aggregation and accumulation procedures, CuMAC/S enables the sender and receiver to employ a speculation procedure for predicting future message values and precomputing the corresponding MAC segments. For the messages which can be reliably speculated, CuMAC/S significantly reduces the MAC verification latency without compromising the cryptographic strength. We have carried out a comprehensive evaluation of CuMAC and CuMAC/S through simulation and a prototype implementation on a real car.

中文翻译：

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资源受限物联网网络的累积消息验证码


在资源有限的物联网网络中，由于 MAC 输出尺寸较大，无法使用传统的消息认证码 (MAC) 来提供消息认证和完整性。解决这个问题的一个简单但幼稚的解决方案是采用截断的 MAC，这会牺牲加密强度以换取减少的通信开销。在本文中，我们通过提出一种称为累积 MAC (CuMAC) 的消息认证新方法来解决这个问题，该方法由两个独特的过程组成：1) 聚合和 2) 累积。在聚合中，发送方通过使用系统编码过程从多个 MAC 段生成紧凑的身份验证标签。在累积过程中，接收方通过收集和验证身份验证标签来累积底层 MAC 的加密强度。通过这两个过程的体现，CuMAC 使接收器能够在加密强度和认证标签处理延迟之间实现有利的权衡。此外，对于一些延迟敏感的消息，这种权衡可能不可接受，我们提出了 CuMAC 的变体，我们将其称为带有推测的 CuMAC (CuMAC/S)。除了聚合和累积过程之外，CuMAC/S 还使发送方和接收方能够采用推测过程来预测未来的消息值并预先计算相应的 MAC 段。对于可以可靠推测的消息，CuMAC/S 在不影响加密强度的情况下显着降低了 MAC 验证延迟。我们通过仿真和在真车上的原型实现对 CuMAC 和 CuMAC/S 进行了全面评估。